com.facebook.battery.metrics.api

Class SystemMetrics<T extends SystemMetrics<T>>

java.lang.Object

com.facebook.battery.metrics.api.SystemMetrics<T>

All Implemented Interfaces:

java.io.Serializable

Direct Known Subclasses:

AppWakeupMetrics, BluetoothMetrics, CameraMetrics, CompositeMetrics, CpuFrequencyMetrics, CpuMetrics, DeviceBatteryMetrics, NetworkMetrics, RadioStateMetrics, TimeMetrics, WakeLockMetrics

public abstract class SystemMetrics<T extends SystemMetrics<T>>
extends java.lang.Object
implements java.io.Serializable

Represents a simple bag of values. SystemMetrics expose all their values as public members, and are generally meant to be recycled if used in hot paths.

The are simply monoids, and can be added/subtracted with utility functions to reset.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
SystemMetrics()

Method Summary

Modifier and Type	Method and Description
T	diff(T b) Convenience wrapper over diff(SystemMetrics, SystemMetrics) which always allocates a new output object.
abstract T	diff(T b, T output) Subtract the object passed in from the current object.
abstract T	set(T b) Sets all fields in this to values from the SystemMetrics object passed in: a _deep_ copy that shouldn't share any values with other metrics objects.
T	sum(T b) Convenience wrapper over sum(SystemMetrics, SystemMetrics) which always allocates a new output object.
abstract T	sum(T b, T output) Add values from the SystemMetrics object passed in and sets them on the output object, if available.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

SystemMetrics

public SystemMetrics()

Method Detail

sum

public abstract T sum(@Nullable
                      T b,
                      @Nullable
                      T output)

Add values from the SystemMetrics object passed in and sets them on the output object, if available. Does not modify the original object. For convenience, this function accepts null values and will allocate an output object if none is passed in.

Parameters:

b -

output -

Returns:

output set to (this + b)

diff

public abstract T diff(@Nullable
                       T b,
                       @Nullable
                       T output)

Subtract the object passed in from the current object. Does not modify the original object. For convenience, this function accepts null values and will allocate an output object if none is passed in.

Parameters:

b -

output -

Returns:

output set to (this - b)

set

public abstract T set(T b)

Sets all fields in this to values from the SystemMetrics object passed in: a _deep_ copy that shouldn't share any values with other metrics objects.

Parameters:

b -

Returns:

this

sum

public T sum(@Nullable
             T b)

Convenience wrapper over sum(SystemMetrics, SystemMetrics) which always allocates a new output object.

Parameters:

b -

Returns:

this + b

diff

public T diff(@Nullable
              T b)

Convenience wrapper over diff(SystemMetrics, SystemMetrics) which always allocates a new output object.

Parameters:

b -

Returns:

this - b